This invention relates to a power assembly comprising a small motor and a gear box. The invention also involves the method of assembling a motor in a gear box wall.
The secure exact positioning of an electric motor on a gear box wall is essential to assure smooth operation and minimal vibration in the operation of the gear train. For this purpose, small electric motors are often provided with a centering or locating collar surrounding the drive shaft. This collar, usually part of the motor housing, fits snugly into an opening in the gear box and is held in place, usually with additional fasteners, to assure proper engagement of the motor spur with a gear within the gear box.
In the past when the spur has been larger than the opening in the gear box, it has been attached to the shaft after the shaft has been extended through the opening. This has been awkward, has produced problems in securing the spur exactly on the axis and is virtually impossible to accomplish by automatic machinery. Ideally, the spur should be attached to the shaft prior to the assembly of the gear box, but this has not been possible when the spur is larger than the opening.
The present invention is directed to the structure and the method of assembly when the spur is slightly larger than the opening. The invention involves the method of assembling a motor to a gearbox wall comprising the steps of providing a motor having a drive shaft mounting a spur or pinion formed with a gear profile having an outside diameter, and a mounting collar surrounding the shaft, the collar having an outside diameter less than the outside diameter of the gear. A gearbox wall formed with a motor-mounting opening having a generally ring-gear shapexe2x80x94or in other words, having notches about its peripheryxe2x80x94of similar but larger configuration than the spur and an inside diameter substantially the same as the outside diameter of the collar. The spur gear is maneuvered through the motor-mounting opening and the collar is pressed into the inside diameter of the motor-mounting opening. The invention is also the structure of the finished assembly including the notched opening.